As is known, for example, from WO 2012/148576 A1, in a device used in the packaging industry for decorating hollow bodies, each of which has a cylindrical lateral surface, in most cases a plurality of printing units are used. In such cases, each of these printing units transfers a printing ink onto a printing blanket, which is used jointly by these printing units. The lateral surface of the hollow body in question is then decorated with a print motif, e.g. a multicolored print motif, by a relative movement between the lateral surface of the hollow body in question and the printing blanket, in particular by rolling the lateral surface of the hollow body in question along said printing blanket, which has been inked-up in advance, particularly with multiple colors.
A device of this type for printing on or for decorating hollow bodies, each of which has in particular a preferably cylindrical lateral surface, is used, for example, in conjunction with a system for producing such hollow bodies, which typically has a plurality of work stations, wherein the hollow bodies are printed on or decorated by means of a printing process, and therefore these hollow bodies may also be referred to generally as printed products. In such a system, the hollow bodies to be printed on are produced in a large-scale production process in which, for example, several hundred or even several thousand pieces are produced per minute, for example between 1500 and 3000 pieces per minute. Hollow bodies of this type are made of metal, in particular steel or aluminum for example, or are made of plastic. Metal hollow bodies of this type are used, for example, as beverage cans or as aerosol cans. Plastic hollow bodies of this type are produced, for example, in the form of thermoplastic molded articles, and are used, for example, as cartons for packaging liquid or paste-like food products, for example, especially dairy products or beverages. However, the hollow body may also be a round tubular body made of either a plastic or aluminum, with a tube being defined as an elongated, sturdy but malleable container, which is intended for filling particularly with a paste-like substance. Tubes made of aluminum are produced, for example, in a backward extrusion process. Tubes made of plastic are produced as seamless tubes, for example, by means of extrusion. Another type of hollow body that can be printed on in an aforementioned device is containers or receptacles, such as bottles or flasks, preferably cylindrical and made of glass.
Beverage cans are preferably made of aluminum and are typically two-part cans, in which a circular base together with a preferably straight cylinder are fabricated in each case from of a single workpiece, i.e. from a slug or from a blank, i.e. a circular disk, in a forming process, for example in a cold extrusion process or in a tension-pressure forming process, preferably by deep drawing, in particular by ironing and deep drawing, to form a hollow body which is open at one end, i.e. a can blank, and in which, in a final fabrication step, a circular lid is placed on the cylinder and is attached to the cylinder by flanging, forming an air-tight seal.
Tinplate cans are another type of can. Tinplate is tin-plated sheet steel. The thickness of the sheet steel used to produce tinplate cans is 0.15 mm to 0.49 mm, for example, and the thickness of the tin plating is 0.2 μm to 0.8 μm, for example; the tin plating provides protection against corrosion. Tinplate cans are three-part cans. To produce the shell for a tinplate can, a rectangular strip of sheet steel is bent into a preferably straight cylinder, and the ends of this strip that has been bent into a cylinder are welded at a butt joint. A circular base and a circular lid are then placed onto the cylinder and the edges are flanged. To give the tinplate can in question greater strength against dents, each of the three parts, i.e., the cylinder, the base and the lid, for example, preferably has a corrugated profile.
An aerosol can, also called a spray can, is a metal can used for spraying liquids. The liquid filled into an aerosol can is pressurized, and propane, butane, dimethyl ether or mixtures thereof, or compressed air or nitrogen, for example, is used as the propellant for dispensing the liquid from the can.
The aforementioned WO 2012/148576 A1 describes a device for decorating cans, in which an assembly of multiple printing units is provided, each having an inking unit for the multicolored decoration of a plurality of cans, wherein each of the inking units belonging to one of the printing units has an ink fountain for supplying ink, wherein in each ink fountain, an ink fountain roller for receiving the printing ink from the associated ink fountain is provided, wherein in each inking unit, an ink ductor is provided, each ink ductor receiving ink from the ink fountain roller in question, wherein in a roller train situated downstream of the respective ink ductor in the inking unit in question, a plurality of oscillating ink distribution rollers and a plurality of ink transfer rollers, each interacting with at least one of the ink distribution rollers, are provided, wherein for each inking unit, a plate cylinder having at least one printing plate is provided, and only a single ink forme roller cooperates with each plate cylinder to apply the ink.
Known from WO 2004/109581 A2 is an apparatus for carrying out a non-contact digital printing method, e.g. an inkjet printing method, for the optionally individual printing of round objects, more particularly two-part cans, without the use of a printing blanket, wherein a plurality of print heads are preferably provided, each of which prints in a single color of ink.
Known from DE 10 2006 004 568 A1 is a short inking unit for a printing machine, comprising a printing forme cylinder, an ink forme roller which cooperates with the printing forme cylinder, and an anilox roller which contacts the ink forme roller and which is assigned a device for supplying ink, wherein at least one leveling roller is located between the point to which ink is supplied and the contact gap between the anilox roller and the ink forme roller, relative to the direction of rotation of the anilox roller, and the device for supplying ink is embodied as a chamber doctor blade.
Known from DE 101 60 734 A1 is a printing machine comprising at least one printing forme, a dampening unit for dampening the printing forme with a dampening medium, an inking unit for inking up the printing forme with an ink, and a dehumidifying device which has a heated roller (temperature control roller) for reducing the amount of dampening medium that is conveyed together with the ink, wherein the inking unit is configured as a leverless short inking unit, wherein an inking unit roller of the inking unit has a first rolling contact point where the inking unit roller is in rolling contact with the heated roller, wherein the inking unit roller has a second rolling contact point, and wherein the shortest conveyance path of the ink from the inking unit roller to the printing forme via at most one intermediate roller is predetermined.
Known from DE 32 32 780 A1 is an inking unit for offset printing machines used for printing sheets or webs with a plate cylinder that receives the necessary ink from at most two ink forme rollers that have an elastic surface and that cooperate with an inking cylinder to which the ink is supplied via an ink feed system that produces a continuous ink film, wherein located downstream of the inking cylinder is an ink forme roller having nearly the same diameter as the plate cylinder, wherein a dampening unit having at least one roller for transferring the dampening medium is assigned to the inking cylinder, and wherein the dampening medium is transferred to the inking cylinder in the direction of rotation thereof, downstream of ink application and upstream of the point of contact between the inking cylinder and the ink forme roller.
Known from DE 10 2006 048 286 A1 is a method for driving a printing unit that has a short inking unit in a processing machine that has an anilox roller and an associated doctor blade device, along with an ink forme roller located downstream of the anilox roller and a plate/forme cylinder downstream of the ink forme roller in the direction of ink flow, wherein the plate/forme cylinder is operatively connected to a rubber blanket cylinder and the rubber blanket cylinder is operatively connected to a printing cylinder which guides the printing substrate, wherein the anilox roller is driven by an independent drive, wherein during printing/varnishing operation, the main drive supplies an input drive to a drive wheel of the printing cylinder and to a drive wheel of the rubber blanket cylinder and to a second and a first drive wheel of the plate/forme cylinder and to a drive wheel of the ink forme roller and to a drive wheel of the anilox roller, while the independent drive of the anilox roller is inactive, and wherein during setup operation, the drive connection to the main drive between first drive wheel and second drive wheel of the plate/forme cylinder is disconnected, the independent drive of the anilox roller is activated, and the independent drive applies drive torque to the drive wheel of the anilox roller and to the drive wheel of the ink forme roller and to the first drive wheel of the plate/forme cylinder.
Known from DE 196 24 440 A1 is a device for filling depressions in a cylinder of a printing machine with a fluid, wherein at least two doctor blade devices for filling depressions in the cylinder with the fluid are arranged on the cylinder, wherein a device for applying the fluid, connected to a conveyance system, and a working doctor blade located downstream of said application device in the direction of rotation of the cylinder are provided, wherein the doctor blades are attached to a bar, and wherein the fluid that is wiped off is drained to a collection basin.
Known from DE 89 12 194 U1 is an inking unit for use in a printing machine, which has a working doctor blade that can be placed against an anilox roller and an ink trough with ink conveying means, wherein the working doctor blade, the ink trough, and the means for conveying the ink to the anilox roller are combined to form a single structural unit, and the structural unit can be removably fastened to a carrier which is mounted on the printing machine.
Known from DE 10 2007 052 761 A1 is an anilox printing unit, comprising as inking unit rollers an ink forme roller and an anilox roller, wherein the anilox roller is mounted on pivoting levers, wherein the anilox roller and the ink forme roller each have bearer rings, and wherein a device for pressing the bearer rings of one inking unit roller against the bearer rings of the other inking unit roller has springs to compensate for diameter differences due to manufacturing tolerances.
Known from DE 28 51 426 A1 is a device for printing the lateral surface of hollow bodies, wherein a transport device is provided for transporting the hollow bodies to be printed about a rotational axis, wherein a plurality of printing units are provided, wherein each hollow body to be printed can be transported by means of the transport device into the printing area of at least one of the printing units, and wherein at least one of the printing units has a printing forme cylinder and an inking unit with a single ink forme roller.
Known from DE 10 2006 032 204 B3 is a method for supplying at least one printing forme to the location where it will be mounted on a forme cylinder of a rotary printing machine, wherein the printing forme, which has been imaged with a print motif, is transported by means of a transport device to the location where it will be mounted on the forme cylinder, wherein the printing forme is transported by means of a transport module that is connected to the transport device, and wherein the printing forme is mounted in its mounting location on the forme cylinder from the transport module.
Known from DE 10 2005 044 223 A1 is a printing unit of a web-fed rotary printing machine, said printing unit having a forme cylinder and a transfer cylinder which rolls on the forme cylinder, wherein a plurality of printing plates can be clamped on the forme cylinder side by side as viewed in the axial direction thereof, and a plurality of printing plates can preferably be clamped on the forme cylinder one in front of the other as viewed in the circumferential direction of the same, said printing unit also having a printing plate changing device assigned to the forme cylinder for the automatic changing of printing plates on the forme cylinder, wherein the printing plate changing device comprises an actuating head that can be moved translationally along the forme cylinder for the purpose of releasing or unlocking, and for securing or locking printing plates on the forme cylinder, and/or a changing cartridge that can be moved translationally along the forme cylinder for the purpose of holding new or replacement printing plates in reserve and for receiving old or replaced printing plates.
Known from DE 40 03 445 A1 is an automatic plate supplying and cylinder loading system for a rotary printing machine, having a handling apparatus for removing a printing plate from a container and applying the printing plate onto a plate cylinder of the printing unit, and also for removing a printing plate from a plate cylinder and placing the printing plate in the container, wherein the handling apparatus is guided along a path that extends substantially parallel to the axis of rotation of the plate cylinder to be loaded, wherein a carriage for transporting a plurality of printing plates up to a printing unit or away from one of these printing units is provided, and wherein the carriage is guided along a path that extends substantially perpendicular to the path of the handling apparatus.
Known from DE 10 2007 035 689 B3 is a method for arranging printing formes on a forme cylinder of a printing machine, wherein one of the printing formes is located in each of a plurality of mounting positions arranged side by side in the axial direction of the forme cylinder, wherein, before being arranged in one of the mounting positions on the forme cylinder, each of the printing formes is stored in a storage position of a storage device which has a plurality of storage positions arranged side by side axially along the forme cylinder and spaced at a fixed distance from one another, wherein once a first printing forme has been arranged on the forme cylinder, this forme cylinder and/or the storage device are displaced axially relative to one another along an adjustment path, such that as a result of this displacement, an additional printing forme to be arranged on the forme cylinder is arranged at a mounting position on the forme cylinder that is located adjacent to the mounting position of the previously arranged printing forme, at a reduced distance relative to the distance between two adjacent storage positions of the storage device.
Known from DE 196 20 997 C2 is a method for axially positioning a printing plate while it is being applied to a cylinder of a rotary printing machine, wherein the printing plate is transported to the cylinder by means of transport means, wherein a section of the cylinder where the printing plate will be applied is selected, wherein a desired position for the printing plate on the cylinder is selected from a plurality of possible, preselectable positions assigned to said cylinder section and lying axially side by side, after which the position of the printing plate in the axial direction relative to a reference position on the cylinder is determined, and wherein finally, the printing plate is moved to the preselected position.
Known from DE 102 39 160 A1 is a printing unit for a printing machine that operates using hard printing plates in an indirect letterpress (letterset) process for printing on round hollow bodies, in particular beverage cans, wherein this printing unit is arranged exchangeably in satellite form on a large central cylinder, wherein rubber blankets that have the same unwinding length as the plate cylinder are located on the central cylinder, wherein the ink is transferred from an ink container via an anilox roller having a cooperating doctor blade device onto an elastic forme roller, wherein the forme roller inks up the plate cylinder with a clamped, hard letterpress plate, and the letterpress plate then transfers the ink to the rubber blanket, wherein an anilox hard roller preferably dips into an ink bath and is provided with a doctor blade device that may be embodied as a negatively engaged doctor blade or as a chamber doctor blade.
Known from WO 98/51500 A1 is an inking unit for a rotary printing machine having ink forme rollers and a forme cylinder, wherein from a central, ink-conducting roller, at least two immediately adjacent ink forme rollers are inked up directly by the central roller, and the ink forme roller is additionally inked up a second time indirectly proceeding from the central roller, wherein the ink forme rollers are preferably each mounted rotatably in a rocker pair, wherein the rocker pairs are arranged so as to pivot about the rotational axis of the central roller, wherein additional rollers in the form of inking rollers and/or rider rollers are arranged rotatably in the rocker pairs, and wherein the rider roller can be thrown on and thrown off of the inking roller and moved out of contact with the ink forme roller.